This is a revision of a proposal to conduct research on the effects of parents' marital historics on the support adult children subsequently provide for their parents and step-parents. Particular attention is given to the effects of the timing of parental marital status changes experienced during childhood. The effect of parental separation, widowhood or remarriage during ones' childhood on the subsequent support provided to parents (custodial, noncustodial and step-parents) by adult children is hypothesized to vary depending on the age of the child at the time of the marital event. In addition, the proposed analysis examines the parental support consequences of the duration of childhood spent in the various living arrangements formed by parental marital status changes. The analysis is based on the National Survey of Families and Households, a nationally representative sample of 13,000 households collected in 1987. Two separate analyses are proposed; the first examines the adult child to parent transfer as reported by the parent and the second examines transfers from adult children to parents as reported by the child. Separate analyses are proposed for biological and step-parent transfers. The types of parental support to be considered are: help with personal problems; household tasks; companionship; transportation; and financial assistance. In addition, a measure of the perceived obligation of adult children to support their parents will be analyzed.